The present invention relates generally to an electronic apparatus, and more particularly to a shield that hides a member, such as a screw, from the outside. The present invention is suitable, for example, for a screw cap that hides a screw used to fix a housing of a portable terminal, such as a cellular phone, a personal handy phone system (“PHS”), and another mobile communication terminal (which are generally referred to as a mobile wireless communication apparatus in this application), a personal digital assistant (“PDA”), and a laptop personal computer (“PC”). The present invention is broadly applicable to an electronic apparatus in addition to the portable terminals, and does not limit an object to be hidden by the shield to the screw.
Recent electronic apparatuses, such as a portable electronic terminal (e.g., a cellular phone and a PDA) are required to have a small, low-profile and lightweight body for portability convenience, as well as having an improved design (or ornamental appearance), economical efficiency, and maintainability to meet users' preferences.
For example, a housing or case of a cellular phone includes screwed front and rear cases. The case is typically made of resin, patterned and colored, while the screw is made of metal, which is a different material from the case, and has a metallic color. The screws when visible on the case is so conspicuous that a user may tend to disassemble and convert the housing, undesirably jeopardizing the safety of the cellular phone. Therefore, a screw cap conventionally hides the screw that fixes the case and its vicinity, which are collectively referred to as a “screw part” hereinafter.
Referring now to FIGS. 7A to 9, a description will be given of the conventional screw cap 10. Here, FIG. 7A is a side view of the screw cap 10, and FIGS. 7B and 7C are perspective views of the screw cap 10 viewed from different angles. FIG. 8 is a plane view with partially enlarged screw caps 10 that cover the screws (not shown) in a cellular phone 2. FIG. 9 is a perspective view for explaining a removal of the screw cap 10.
The conventional screw cap 10 has an approximately triangle shape and includes, as shown in FIG. 7, a chamfered, approximately triangle top 12, a bevel 14 at the edge, and a bottom 15. A notch 16 is formed at the center of the bevel 14. In assembly, a double-sided tape is adhered to the bottom 15 of the screw cap 10, and the screw caps 10 are then attached to screw parts 4, a pair of right and left dents, in the cellular phone 2 as shown in FIG. 8. The screw cap 10 covers the screw part 4 and does not expose the screw under the top 12. The top 12 is level with the case, and made of the same material and color as those of the case 6, maintaining the design or appearance continuity at the screw parts 4.
In disassembly of the case 6 by detaching the screws for maintenance, the screw caps 10 are removed from the case 6 so as to expose the screws. In removing the screw caps 10 from the case 6, a pointed tool 20 is inserted into the notch 16 in the screw cap 10, as shown in FIG. 9, and an upper force is applied via the tip of the tool 20 against the adhesion of the double-sided tape by leverage.
The screw cap itself is also known in the art unrelated to the art of the inventive electronic apparatus. See, for example, Japanese Patent Applications, Publication Nos. 2000-16224 (elements 32a and 32b in FIG. 1 and Paragraph Nos. 0024 and 0029), and 2000-300720 (screw caps 150 and 157 in FIGS. 1, 4 and 7).
Disadvantageously, in inserting the tool 20 into the notch 16 in the screw cap 10 and removing the screw cap 10 from the case, the edge of the case 6 opposing to the notch 16 may possibly get damaged. Since the notch 16 is provided at the boundary with the case 6, the tool 20 inserted into the notch 16 easily damages the edge of the case 6 opposing to the notch 16. The fulcrum of the leverage is the edge of the case 6 opposing to the notch 16, and the tool 20 inserted into the notch 16 and powered easily damages the edge of the case 6 opposing to the notch 16. In particular, the typical tool 20 often uses metal tweezers, which is stronger than the resin case 6, and easily damages the case 6. In removing the screw cap 10, the tool 20 is forced onto the bottom 15 of the screw cap 10, and the screw cap 10 gets damaged. Therefore, the screw cap 10 is replaced at the maintenance. However, if the case 6 gets damaged and needs a replacement, the cost would increase. The maintenance that does not damage the case 6 needs skills and a longer maintenance time period. Thus, the conventional screw cap 10 has the bad maintainability (or disassembly performance). In particular, as the screw cap 10 becomes smaller and thinner for a smaller and thinner housing, the operability lowers remarkably.
The instant inventors have reviewed arranging a perforation hole in the (top surface of the) screw cap 10 instead of arranging the notch 16 around the screw cap 10. This configuration can protect the edge of the case 6 from damages in inserting the tool 20 into the perforation hole and removing the screw cap 10 by leverage. However, the perforation hole in the screw cap 10 highlights the screw cap 10 and generally deteriorates both the appearance continuity and safety, due to a double hole effect of the perforation hole and the dent hole into which the screw cap 10 is inserted. The screw cap 10 is preferably quiet for both the appearance continuity and safety. In addition, the perforation hole in the top surface 10 exposes the screw through the hole, contrary to the objective of the provision of the screw cap 10.
Instead of the metal tweezers for the tool 20, it is also conceivable to use a resin material similar to that of the case 6 or a softer material so as to prevent damages of the case 6. This measure, however, is impracticable since the double-sided tape has a comparatively strong adhesion and easily breaks a tip of the resin member. On the other hand, if the adhesion of the double-sided tape is made weaker so that the screw cap 10 is easily removed, the screw cap 10 would be undesirably removed from the cellular phone 2 and may possibly be lost at the non-maintenance time, for example, when an impact is applied to the cellular phone 2.
In addition, like the screw caps 10A and 10B in FIG. 8, a pair of screw caps 10 are not formed in bilateral symmetry because they have notches 16A and 16B at different positions. Due to the manufacture of these two differently shaped screw caps 10A and 10B, the conventional screw cap has the bad manufacturing performance, and increases the manufacturing cost.